Immunoglobulin gene rearrangements in B-cell lymphoma subtypes may not always be detected by PCR if only one primer set is applied. We therefore analysed a range of low and high grade B-cell lymphoma subtypes for monoclonality using PCR, to determine appropriate primer selection strategies for routine diagnostic use. Semi-nested PCR was performed on 70 unequivocal B-cell lymphoma cases using paraffin-embedded tissue (PET). Consensus primers directed at the framework 3 (Fr3) and framework 2 (Fr2) regions of the immunoglobulin heavy chain (IgH) gene were used to detect monoclonality. Monoclonality was found in 77% of cases using primer Fr3, 58% using Fr2, and in 93% of cases when data were combined for both primers. In 89% of the 38 low grade and 97% of the 31 high grade B-cell lymphomas monoclonality could be detected when combining both primers. Fr3 gave superior results in most of the lymphoma subtypes analysed. We conclude that both Fr3 and Fr2 are useful, in a routine histopathology laboratory, for detecting monoclonality in most B-cell lymphoma subtypes. Certain subtypes, however, are sometimes not targeted by these primers and therefore require additional analyses.